With the rapid development of Internet application and intelligent terminal, the requirement of users for accessing, through various intelligent terminals, such as smart phone and tablet computer, the Internet to work anytime and anywhere is widely popularized, one of the most important methods is that users access a network through a WLAN network.
As shown in FIG. 1, a traditional WLAN network includes an Access Point (AP), an Access Controller (AC), an Authentication, Authorization and Accounting (AAA) server and other network elements; a user terminal, after being authenticated by the AAA server, can access a network through the AP and the AC; the AC manages and controls the AP device through a Control And Provisioning of Wireless Access Points Protocol (CAPWAP). With the development of network convergence trend, convergence of the WLAN network and a fixed broadband network becomes one of future mainstream trends; as shown in FIG. 2 and FIG. 3, all types of user terminals access the fixed broadband network through the WLAN network and a wired link; user authentication and service control are performed by a Broadband Network Gateway (BNG), and the AC of the WLAN network only takes charge of management and service configuration of the AP. In the meantime, the requirement of emerging Internet applications to network quality becomes higher and higher, operators put forward higher requirements for safety and quality of service of the WLAN network, and require that the WLAN network can provide bandwidth assurance, security encryption and other functions, and can provide different levels of services based on subscription situations of different users. Under the situation that the BNG device uniformly performs WLAN and wired broadband user authentication, the AC cannot perceive user subscription situation, which causes that the WLAN network cannot provide security and bandwidth assurance and other functions based on user subscription information.